The present invention relates to a printing apparatus for printing sheets and selectively depositing the printed sheets on supports which are adjustable in height, independent of each other, by utilizing a sheet deposition member disposed at a fixed location. Each support is movable between the highest deposition position and the lowest deposition position in which sheets can be deposited on the associated support. Each support is adapted to be positioned in a parking position in which sheets are not deposited on the associated support and in which the parking position of the bottom support is no higher than the lowest deposition position of the bottom support and the parking position of the supports situated above the bottom support is higher than the fixed sheet deposition member. A printing apparatus of this kind is known from European Patent 0 532 069.
Printing apparatus, including apparatus of the type indicated above, is increasingly used by different users who send images for printing to the printing apparatus via an electronic network from a location remote from the printing apparatus, and also start the printing apparatus at a location remote from the printing apparatus, e.g. from a workstation at the user""s workplace. When users of this kind do not go to the printing apparatus in order to directly remove the prints after the sheets printed from them have been completed, but rather leave them there until a suitable future time occurs, there is the risk that prints from other users, who are also not present at the printing apparatus will land on the previous prints and fill the available deposition space at the printing apparatus. In the case of a printing apparatus of the type referred to in the preamble, in which the space required for moving the supports up and down is appreciably less than twice the space occupied by a maximum number of sheets to be deposited on the supports, the non-removal of said sheets results in a limitation of the available deposition space.
The object of the present invention is to provide a printing apparatus of the type referred to in the preamble, which can be operated both by a user at a distance from the printing apparatus and by a user located at the printing apparatus, while eliminating the problems discussed hereinabove. To this end, and according to the present invention, the printing apparatus is provided with a control key for setting the printing apparatus to the deposition of printing sheets on the bottom support. With this setting, each support situated above the bottom support is in its parking position and the bottom support is in its deposition position. When the printing apparatus is set to deposit printed sheets onto a support situated above the bottom support, then the bottom support is in its parking position and the support thereabove selected for deposition is in its deposition position. As a result, prints from a user who has started the printing operation by operating the control key on the printing apparatus arrive on the bottom support and can be removed directly, after printing, by the operator present at the printing apparatus.
A printing cycle of images originating from a workstation situated at a distance from the printing apparatus, which is activated at a printing apparatus, is known per se from European Patent 0 208 342. However, when an operator is located at the printing apparatus for the purpose of activating the same and immediately removes the finished prints, in the printing apparatus according to the present invention there are never a large number of prints on the bottom support so that the supports situated above the bottom support can be lowered to a point just above the parking position of the bottom support, in the absence of an operator at the printing apparatus, in order thus to create a maximum deposition space for prints for which the printing apparatus has been activated remotely by users at their workplace. The automatic production of prints without an operator being located at the printing apparatus can be restricted to bulky orders, e.g. multiple copy printing of reports, on supports situated above the bottom support, while the production of prints for which an operator should be located at the printing apparatus applies to the rest of the orders, e.g. small orders, the users of which are distributed over their own workplaces.
In one advantageous embodiment of the printing apparatus according to the present invention, the control key is formed by a start key on the printing apparatus, which when actuated, not only sets the printing apparatus to deposit printed sheets on the bottom support but also starts the printing of sheets which are to be deposited on the bottom support. As a result, no special control key has to be provided on the printing apparatus to ensure that the printed sheets in the case of prints initiated at the actual printing apparatus are deposited onto the bottom support of a number of supports, each independently adjustable as to height.
Preferably, the parking position of the bottom support is situated at a fixed predetermined distance below the lowest deposition position of the bottom support. As a result, the support situated directly above the bottom support is movable between its highest deposition position and its lowest deposition position without sheets deposited on the bottom support having to be removed. Thus, the support situated immediately above the bottom support can always be placed directly in its deposition position, this naturally being advantageous for the deposition of printed sheets during an interruption of a running print order (i.e., for an intermediate print order).
In another advantageous embodiment of a printing apparatus according to the present invention, the top support of the supports which are adjustable independently of one another is adapted to be placed in its bottom deposition position only when there are no sheets situated between at least two supports positioned lower than the fixed sheet deposition member. As a result, the supports can be placed as close as possible to one another so that a high deposition capacity is achieved in a relatively small deposition space.